25 research outputs found
OpenMP tasking model for Ada: safety and correctness
22nd International Conference on Reliable Software Technologies (Ada-Europe 2017). 12 to 16, Jun, 2017. Vienna, Austria.The safety-critical real-time embedded domain increasingly demands the use of parallel architectures to fulfill performance requirements. Such architectures require the use of parallel programming models to exploit the underlying parallelism. This paper evaluates the applicability of using OpenMP, a widespread parallel programming model, with Ada, a language widely used in the safety-critical domain.
Concretely, this paper shows that applying the OpenMP tasking model to exploit fine-grained parallelism within Ada tasks does not impact on programs safeness and correctness, which is vital in the environments where Ada is mostly used. Moreover, we compare the OpenMP tasking model with the proposal of Ada extensions to define parallel blocks, parallel loops and reductions. Overall, we conclude that the OpenMP tasking model can be safely used in such environments, being a promising approach to exploit fine-grain parallelism in Ada tasks, and we identify the issues which still need to be further researched.info:eu-repo/semantics/publishedVersio
Epidemiology of cervical spine fractures in the US military
BACKGROUND CONTEXT: The epidemiology of cervical spine fractures and associated spinal cord injury (SCI) has not previously been estimated within the American population.
PURPOSE: To determine the incidence of cervical spine fractures and associated SCI and identify potential risk factors for these injuries in a large multicultural military population.
STUDY DESIGN: Query of a prospectively collected military database.
PATIENT SAMPLE: The 13,813,333 military service members serving in the US Armed Forces between 2000 and 2009.
OUTCOME MEASURES: The Defense Medical Epidemiology Database (DMED) was queried to identify all service-members diagnosed with cervical spine fractures with and without SCI during the time period under investigation. Data were used to determine the incidence of cervical spine fractures and SCI as well as identify risk factors for their development.
METHODS: The DMED was queried for the years 2000 to 2009 using the International Classification of Diseases, Ninth Revision, Clinical Modification code for cervical spine fractures with and without SCI (805.0, 805.1, 806.0, and 806.1). The database was also used to determine the total number of service-members within the military during the same period. The incidence of cervical spine fractures and fractures associated with SCI was determined, and unadjusted incidence rates were calculated for the demographic characteristics of sex, race, military rank, branch of service, and age. Adjusted incidence rate ratios were then determined using multivariate Poisson regression analysis to control for other factors in the model and identify significant risk factors for cervical spine fractures and cervical injuries associated with SCI.
RESULTS: From 2000 to 2009, there were 4,048 cervical spine fractures in a population at risk of 13,813,333 service-members. The overall incidence of cervical spine fractures was 0.29 per 1,000 person-years, and the incidence of fracture associated SCI was 70 per 1,000,000. The cohorts at highest risk of cervical spine fracture were males, whites, Enlisted personnel, those serving in the Army, Navy, or Marine Corps, and servicemembers aged 20 to 29. Risk of fracture associated SCI was significantly increased in males, Enlisted personnel, service-members in the Army, Navy, or Marines, and those aged 20 to 29.
CONCLUSIONS: This study is the largest population-based investigation to be conducted within the United States regarding the incidence of SCI and the only study addressing incidence and risk factors for cervical spine fractures. Male sex, white race, Enlisted military rank, service in the Army, Navy, or Marine Corps, and ages 20 to 29 were found to significantly increase the risk for cervical fractures and/or fracture associated SCI. Our findings support previously published data but also represent best available evidence based on the size and diversity of the population under study.
LEVEL OF EVIDENCE: Prognostic; Level II
Chitosan-hydroxyapatite composites in biomedical applications
W pracy przedstawiono sposoby wytwarzania scaffoldów w oparciu o chi-tozan i hydroksyapatyt. Przedstawiono wstępnie badania własne nad możliwością wytarzania temowrażliwych hydrożeli chitozanowych i hydrożelo-wych membran formowanych w wyniku reakcji polianion-polikation, które zawierają w strukturze wapń i fosfor. Obecność w strukturze wapnia daje możliwość wykorzystania ich jako opatrunków o zwiększonych własnościach zakrzepowych, a obecność oprócz wapnia również fosforu predysponuje do zastosowania jako scaffoldów do hodowli komórkowej.Methods of preparation of chitosan- and hydroxyapatite-based scaffolds are described in the paper. The authors present preliminary results of their studies on the preparation of themosensitive chitosan hydrogels and hydrogel membranes containing calcium and phosphorus in their structure via poly-anion-polycation reactions. A presence of calcium in the structure provides a possibility to use them as dressings with enhanced thrombotic properties, while the presence of phosphorus, beside calcium, predestines them to be applied as scaffolds in cell cultures
Włókniny poliwęglanowe modyfikowane plazmą jako materiał filtracyjny dla ciekłych aerozoli
The filter materials commonly used in filtration processes consist of nonwoven fabrics made by melt blowing. In order to improve filtration properties they are subjected to various modifications. This paper presents the treatment of polycarbonate nonwovens with lowpressure cold plasma generated by a 13.56 MHz RF discharge using process gases such as Ar and O2. The effectiveness of such treatment was assessed on the basis of results of the penetration of nonwovens by paraffin oil mist as well as the air flow resistance. The effects of plasma on polycarbonate nonwovens, especially on their surface morphology and chemical structure, were evaluated by electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The results indicate that Ar plasma is a good tool for improving the filtration properties of polycarbonate filtering materials. According to these results, the surface roughness plays an important role in the high-efficiency filtration of liquid aerosols with a small increase in air flow resistance.Materiały filtrujące powszechnie stosowane w procesach filtracji to przede wszystkim włókniny wykonane techniką melt-blown. W celu poprawy ich właściwości filtracyjnych są poddawane różnym modyfikacjom. W artykule przedstawiono obróbkę włókniny poliwęglanowej za pomocą zimnej plazmy niskociśnieniowej RF 13,56 MHz przy użyciu gazów procesowych, takich jak argon (Ar) i tlen (O2). Skuteczność takiej obróbki oceniano na podstawie wyników penetracji aerozolu mgły oleju parafinowego przez włókniny oraz oporów przepływu powietrza. Efekt obróbki plazmowej włóknin otrzymywanych z poliwęglanu, zwłaszcza w ich morfologii powierzchni i struktury chemicznej, badano za pomocą mikroskopii skaningowej (SEM), energetycznie-dyspersyjnej spektroskopii rentgenowskiej (EDX) oraz rentgenowskiej spektroskopii fotoelektronów (XPS). Wyniki wskazują, że plazma w argonie jest dobrym narzędziem do poprawy właściwości filtracyjnych włóknin otrzymywanych z poliwęglanu. Na podstawie tych wyników wykazano, że chropowatość powierzchni odgrywa ważną rolę w wysokiej skuteczności filtracji ciekłych aerozoli z małym wzrostem oporu przepływu powietrza
Integrated stand for the fiber optics technique operations
W artykule przedstawiono zintegrowane stanowisko pozwalające wykonywać operacje spotykane w laboratoryjnej praktyce techniki światłowodowej i badać poprawność ich realizacji. W szczególności możliwe jest przygotowanie końcówki światłowodowej za pomocą cięcia, klejenia żywicą, szlifowania z polerowaniem czoła światłowodu. Dodatkowe wyposażenie pozwala również na montaż elementów optoelektronicznych ze światłowodami. W artykule zamieszczono wyniki badań wykonanych końcówek światłowodowych.In the paper a integrated stand for the optical fiber technique operations met in the laboratory practice is presented. The stand allows preparing the fiber ends using such operations as cutting, gluing with epoxy resin, end surface grinding and polishing as well as the quality study of prepared ends. An additional equipment makes possible to assemble optoelectronics elements with optical fibers. Some results of the prepared optical fiber ends are given